Electric Sofa Stent

ABSTRACT

An electric sofa stent comprising two coupled assemblies, a drive link and a motor drive. When the motor drive is driving the drive link into rotation, the headrest is driven to rotate via the coupled assemblies. Each of the coupled assemblies comprises of a first connector, a second connector, a third connector, a first fixture and a headrest connector. One end of the first connector is fixedly connected to the drive link, and the other end is pivot connected to one end of the second connector. The other end of the second connector is pivot connected to one end of the third connector. The other end of the third connector is pivot connected to the first fixture, which is fixed on the side frame. The upper end of the headrest connector is fixedly connected to the headrest, and the lower end is pivot connected to the third connector.

RELATED APPLICATIONS

This application claims priority to China Patent Application No. CN201621434247.5, filed Dec. 26, 2016.

The applications and all patents, patent applications, articles, books, specifications, other publications, documents, and things referenced herein are hereby incorporated herein in their entirety for all purposes. To the extent of any inconsistency or conflict in the definition or use of a term between any of the incorporated publications, documents, or things and the text of the present document, the definition or use of the term in the present document shall prevail.

BACKGROUND OF THE INVENTION Technical Field

The present invention relates to an electric sofa stent, and belongs to the field of sofa stent structural design.

Related Art

Commonly, angles of a headrest on furniture such as a seat or a sofa can be adjusted to meet the comfort requirement of the consumers. One of the most direct manners to achieve this design is to set a hinge, which is connected with the headrest in the seat or sofa, and the angle of the headrest is changed when the headrest pivots with the hinge. As such, the consumer can adjust the tilting angle of the headrest according to his actual requirement to obtain a desired comfort.

One prior art discloses an electric sofa stent comprising a linear drive device and at least one adjustment assembly. The adjustment assembly includes a side plate, a slide piece, a first link and a second link. The slide piece is slidably disposed at the side plate, and the linear drive device is driving the slide piece to slide on the side plate. One end of first link is pivot connected to the slide piece. The other end of first link is pivot connected to one end of second link. The other end of second link is an end fixed to headrest. The second link is also pivot connected to the side plate, and the pivot connection is positioned between the two ends of second link. During operation, the linear drive device drives the slide piece to slide on the side plate. The sliding slide piece drives, via first link, the second link to rotate in relative to side plate, enabling the angle of second link, at the end fixed to headrest, to be changed in relative to the side plate. Hence, the headrest can be adjusted arbitrarily to any required angle or position without restriction, and can be readjusted back by a simple opposite operation of the linear drive device. However, even though the above electric sofa stent can meet the purpose of automatic adjustment of headrest angle, the electric sofa stent has no security protection. In the installation process, the headrest forms a clear gap with the backrest after a certain angle of outward rotation. If the user rotates the headrest backward to resume its original position, the gap between headrest and backrest will gradually become smaller. At this moment, if someone at the rear of sofa place his hand accidentally in the gap and unable to withdraw it timely, hand injury may occurs. Therefore, its operation is not safe.

SUMMARY OF THE INVENTION

In view of the prior art, one objective of one embodiment of the present invention is to provide an electric sofa stent with a rational structure. The back and forth angles of the headrest are adjustable, and with an enhanced operation safety.

A technical solution is provided to achieve one objective of one embodiment of the present invention:

An electric sofa stent, comprises of two symmetrically disposed coupled assemblies, a drive link connecting the two coupled assemblies and a motor drive able to drive the drive link into rotation. The bottom ends of the two coupled assemblies are fixedly connected with the two ends of the drive link respectively. The top ends of the two coupled assemblies are fixedly connected with the two ends of the headrest respectively. When the motor drive is driving the drive link to rotate in forward and backward direction, the headrest is driven to rotate forward and backward via the coupled assemblies. Each of the coupled assemblies comprises of a first connector, a second connector, a third connector, a first fixture and a headrest connector. One end of the first connector is fixedly connected to a corresponding end of the drive link. The other end of the first connector is pivot connected to one end of the second connector. The other end of the second connector is pivot connected to one end of the third connector. The other end of the third connector is pivot connected to the first fixture. The first fixture is fixed on the side frame. The upper end of the headrest connector is fixedly connected to the headrest. The lower end of the headrest connector is pivot connected to the third connector, so that the headrest connector can rotate around its pivot joint with the third connector. A first limiting structure is provided between the headrest connector and the third connector to restrict the rotation angle of the headrest connector in relative to the third connector. A tension spring is provided between the headrest connector and the third connector, to provide a backward pull to the headrest connector. One end of the tension spring is connected to the headrest connector, and the other end is connected to the third connector.

In one embodiment of the present invention, the first limiting structure comprises of a first arcuate limiting slot formed on the third connector or headrest connector and a first limiting stub fixed on the headrest connector or third connector mating with the first arcuate limiting slot. When the headrest connector rotates in relative to third connector, the first limiting stub moves in the first arcuate limiting slot.

In one embodiment of the present invention, a second limiting structure is provided on the side frame to restrict the rotation angle of the first connector.

In one embodiment of the present invention, the second limiting structure comprises of a second fixture fixed on side frame, a second arcuate limiting slot formed on the second fixture or first connector, and a second limiting stub fixed on the first connector or second fixture mating with the second arcuate limiting slot. When the second connector rotates in relative to the second fixture, the second limiting stub moves in the second arcuate limiting slot.

The present invention has a positive effect: With the structure of one embodiment of the present invention, see FIG. 1, normally, the headrest and the third connector remain relatively stationary to each other under the coordinated action of first limiting structure and tension spring, and the headrest can withstand the frontal pressure. When adjusting the back and forth angles of headrest, the motor drive is driving the drive link to rotate, and the headrest is driven to rotate forward and backward around the pivot joint (part a in the figure) between the first fixture and third connector, via the coupled assemblies, so that the back and forth angles of the headrest can be controlled by the forward and backward rotation of the motor drive, and the headrest can stop at the appropriate position when the motor drive stops to operate. In actual use, if someone accidentally extends his hand between the headrest and the backrest, a resistance force F (see FIG. 4) from the hand will act on the headrest during the backward rotation process of the headrest. Hence, the headrest will, around the pivot joint (part b in the figure) between the headrest connector and the third connector, rotate forward and further stretches the tension spring, thereby yielding a cushioning protection, which prevents the headrest, during a backward rotation, from pinching the hand, thus improves the safety of sofa operation. After the hand is withdrawn from the gap, resistance F is removed, the headrest will turn around the pivot joint (part b in the figure) and resettle through a backward rotation under the action of tension spring.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of one embodiment of the electric sofa stent.

FIG. 2 is a front elevation view diagram of one embodiment of the electric sofa stent.

FIG. 3 is a cross-sectional schematic diagram along A-A in FIG. 2.

FIG. 4 is a schematic diagram with resistance force F acting on one embodiment of the headrest during its resettling through a backward rotation.

FIG. 5 is a schematic diagram of one embodiment of the electric sofa stent (with some parts omitted).

FIG. 6 is a schematic diagram of one embodiment of the coupled assemblies with the headrest connector omitted.

DETAILED DESCRIPTION OF THE INVENTION

By the following accompanied figures, the structure of one embodiment of the electric sofa stent will be more specifically described.

An electric sofa stent, as shown in FIG. 1 to FIG. 6, comprises of two symmetrically disposed coupled assemblies 1, a drive link 3 connecting the two coupled assemblies and a motor drive 2 able to drive the drive link 3 into rotation. The bottom ends of the two coupled assemblies 1 are fixedly connected with both ends of the drive link 3 respectively. The top ends of the two coupled assemblies 1 are fixedly connected with both ends of the headrest 4 respectively. When the motor drive 2 is driving the drive link 3 to rotate in forward and backward direction, the headrest 4 is driven to rotate forward and backward via the coupled assemblies 1. The motor drive 2 used in present embodiment is a motor drive of the prior art. Its structure belongs to the prior art, and will not be repeated in detail here. Each of the coupled assemblies 1 comprises of a first connector 11, a second connector 12, a third connector 13, a first fixture 14 and a headrest connector 15. One end of the first connector 11 is fixedly connected to a corresponding end of the drive link 3. The other end of the first connector 11 is pivot connected to one end of the second connector 12. The other end of the second connector 12 is pivot connected to one end of the third connector 13. The other end of the third connector 13 is pivot connected to the first fixture 14. The first fixture 14 is fixed on the side frame 5. The upper end of the headrest connector 15 is fixedly connected to the headrest 4. The lower end of the headrest connector 15 is pivot connected to the third connector 13, so that the headrest connector 15 can rotate around its pivot joint (part b in the figure) with the third connector 13. A first limiting structure is provided between the headrest connector 15 and the third connector 13 to restrict the rotation angle of the headrest connector 15 in relative to the third connector 13. The rotation angles of the headrest connector 15, as restricted by the first limiting structure, in relative to the third connector 13 is within 45°, such as 15°, 25°, 35° etc. A tension spring 6 is provided between the headrest connector 15 and the third connector 13, to provide a backward pull to the headrest connector 15. One end of the tension spring 6 is connected to the headrest connector 15, and the other end is connected to the third connector 13. With the structure of present invention, see FIG. 1, normally, the headrest 4 and the third connector 13 remain relatively stationary to each other under the coordinated action of first limiting structure and tension spring 6, and the headrest 4 can withstand the frontal pressure. When adjusting the back and forth angles of headrest 4, the motor drive 2 is driving the drive link 3 to rotate, and the headrest 4 is driven to rotate forward and backward around the pivot joint (part a in the figure) between the first fixture 14 and third connector 13, via the coupled assemblies 1, so that the back and forth angles of the headrest 4 can be controlled by the forward and backward rotation of the motor drive 2, and the headrest 4 can stop at the appropriate position when the motor drive 2 stops to operate. In actual use, if someone accidentally extends his hand between the headrest and the backrest, a resistance force F (see FIG. 4) from the hand will act on the headrest during the backward rotation process of the headrest. Hence, the headrest will, around the pivot joint (part b in the figure) between the headrest connector 15 and the third connector 13, rotate forward and further stretches the tension spring, thereby yielding a cushioning protection, which prevents the headrest, during a backward rotation, from pinching the hand, thus improves the safety of sofa operation. After the hand is withdrawn from the gap, resistance F is removed, the headrest will turn around the pivot joint (part b in the figure) and resettle through a backward rotation under the action of tension spring.

In one embodiment of the present invention, the first limiting structure comprises of a first arcuate limiting slot 8 formed on the headrest connector 15 and a first limiting stub 9 fixed on the third connector 13 mating with the first arcuate limiting slot 8. When the headrest connector 15 rotates in relative to third connector 13, the first limiting stub 9 moves in the first arcuate limiting slot 8, thereby limiting the rotation angle of headrest connector 15 in relative to the third connector 13. As a variation of the structure, the first limiting structure may also use the following structure: it comprises of a first arcuate limiting slot 8 formed on the third connector 13 and a first limiting stub 9 fixed on the headrest connector 15 mating with the first arcuate limiting slot 8. When the headrest connector 15 rotates in relative to third connector 13, the first limiting stub 9 moves in the first arcuate limiting slot 8,

As an improvement of one embodiment of the present invention: see FIGS. 3-5, a second limiting structure is provided on the side frame 5 to restrict the rotation angle of the first connector 11. Furthermore, the second limiting structure comprises of a second fixture 7 fixed on the side frame 5, a second arcuate limiting slot 10 formed on the second fixture 7 or first connector 11, and a second limiting stub 101 fixed on the first connector 11 or second fixture 7 mating with the second arcuate limiting slot 10. When the second connector 12 rotates in relative to the second fixture 7, the second limiting stub 101 moves in the second arcuate limiting slot 10, thereby limiting the rotation angle of second connector 12 in relative to the second fixture 7.

The above embodiments described thereof serves only as an illustration of the scope of present invention with no limitation to the implementation of present invention. It will be understood by those skilled in the art that various changes or supplements in form and details may be made therein without departing from the scope of the invention as defined by the appended claims. It is not necessary and impossible to list out all possible methods of implementation herewith.

While the present invention has been described in detail and cited with reference to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention.

LIST OF REFERENCE NUMERALS

1 coupled assembly

11 first connector

12 second connector

13 third connector

14 first fixture

15 headrest connector

2 motor drive

3 drive link

4 headrest

5 side frame

6 tension spring

7 second fixture

8 first arcuate limiting slot

9 first limiting stub

10 second arcuate limiting slot

101 second limiting stub 

What is claimed is:
 1. An electric sofa stent, comprising: two symmetrically disposed coupled assemblies (1); a drive link (3) connecting the two coupled assemblies; a motor drive (2) capable of driving the drive link (3) into rotation; bottom ends of the two coupled assemblies (1) fixedly connected with ends of the drive link (3); top ends of the two coupled assemblies (1) are fixedly connected with ends of a headrest (4); a first connector (11) on each coupled assembly (1), a first end of the first connector (11) fixedly connected to a corresponding end of the drive link (3) a second connector (12) on each coupled assembly (1), a second end of the first connector (11) pivot connected to a first end of the second connector (12); a third connector (13) on each coupled assembly (1), a second end of the second connector (12) pivot connected to a first end of the third connector (13); a first fixture (14) on each coupled assembly (1), a second end of the third connector (13) pivot connected to the first fixture (14), the first fixture (14) fixed on a side frame (5); a headrest connector (15) on each coupled assembly (1), an upper end of the headrest connector (15) fixedly connected to the headrest (4); a lower end of the headrest connector (15) pivot connected to the third connector (13) such that the headrest connector (15) is capable of rotating around a pivot joint of the headrest connector (15) with the third connector (13); a first limiting structure provided between the headrest connector (15) and the third connector (13) to restrict a rotation angle of the headrest connector (15) relative to the third connector (13); and a tension spring (6) provided between the headrest connector (15) and the third connector (13), capable of providing a backward pull to the headrest connector (15), a first end of the tension spring (6) connected to the headrest connector (15), a second end of the tension spring (6) connected to the third connector (13); wherein when the motor drive (2) is driving the drive link (3) to rotate in a forward and backward direction, the headrest (4) is driven to rotate forward and backward via the coupled assemblies (1).
 2. The electric sofa stent according to claim 1, further comprising: a first arcuate limiting slot (8) of the first limiting structure, the first arcuate limiting slot (8) formed on the third connector (13) or on the headrest connector (15); and a first limiting stub (9) of the first limiting structure, the first limiting stub (9) fixed on the headrest connector (15) or on the third connector (13), the first limiting stub (9) mating with the first arcuate limiting slot (8); wherein when the headrest connector (15) rotates relative to the third connector (13), the first limiting stub (9) moves in the first arcuate limiting slot (8).
 3. The electric sofa stent according to claim 1, further comprising: a second limiting structure provided on the side frame (5) to restrict a rotation angle of the first connector (11).
 4. The electric sofa stent according to claim 3, further comprising: a second fixture (7) of the second limiting structure, the second fixture (7) fixed on an inner side of the side frame (5); a second arcuate limiting slot (10) formed on the second fixture (7) or on the first connector (11); and a second limiting stub (101) of the second limiting structure, the second limiting stub (101) fixed on the first connector (11) or on the second fixture (7), the second limiting stub (101) mating with the second arcuate limiting slot (10); wherein when the second connector (12) rotates relative to the second fixture (7), the second limiting stub (101) moves in the second arcuate limiting slot (10).
 5. The electric sofa stent according to claim 2, further comprising: a second limiting structure provided on the side frame (5) to restrict a rotation angle of the first connector (11).
 6. The electric sofa stent according to claim 6, further comprising: a second fixture (7) of the second limiting structure, the second fixture (7) fixed on an inner side of the side frame (5); a second arcuate limiting slot (10) formed on the second fixture (7) or on the first connector (11); and a second limiting stub (101) of the second limiting structure, the second limiting stub (101) fixed on the first connector (11) or on the second fixture (7), the second limiting stub (101) mating with the second arcuate limiting slot (10); wherein when the second connector (12) rotates relative to the second fixture (7), the second limiting stub (101) moves in the second arcuate limiting slot (10). 